Ingestion of Hawthorne root can cause what false-positive laboratory test?
False positive serum digoxin concentration. Hawthorne root (Crategus mexicana) with the Spanish common name “raiz de tejocote”, contains flavonoids that appear to cross-react with the digoxin assay. Two case reports found apparent digoxin concentrations of 0.7 ng/mL in one and 0.9 ng/mL in the other (Rx range 0.5 to 2.0 ng/mL). Both cases had bradycardia. Neither case had hyperkalemia. One received 2 vials of digoxin Fab without apparent effect. The other patient improved over several hours without without Fab. Whether there is any role for digoxin Fab for Hawthorne root remains uncertain.
“Palmer KG, Lebin JA, Cronin MT, Mazor SS, Burns RA. Crataegus mexicana (Tejocote) exposure associated with cardiotoxicity and a falsely elevated digoxin level. J Med Toxicol. 2019;15(4):295-298. doi: 10.1007/s13181-019-00727-w. PMID: 31407210. Espinosa J, Bassett R, Lucerna A, Finn D. Hawthorne root (Crataegus mexicana) toxicity.
Am J Emerg Med 2024;78:242.e5-242.e6. doi: 10.1016/j.ajem.2023.10.046. ”
Contributed by Michael Mullins, MD